001    /*
002     $Id: GStringExpression.java 3419 2006-01-19 00:07:02Z blackdrag $
003    
004     Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005    
006     Redistribution and use of this software and associated documentation
007     ("Software"), with or without modification, are permitted provided
008     that the following conditions are met:
009    
010     1. Redistributions of source code must retain copyright
011        statements and notices.  Redistributions must also contain a
012        copy of this document.
013    
014     2. Redistributions in binary form must reproduce the
015        above copyright notice, this list of conditions and the
016        following disclaimer in the documentation and/or other
017        materials provided with the distribution.
018    
019     3. The name "groovy" must not be used to endorse or promote
020        products derived from this Software without prior written
021        permission of The Codehaus.  For written permission,
022        please contact info@codehaus.org.
023    
024     4. Products derived from this Software may not be called "groovy"
025        nor may "groovy" appear in their names without prior written
026        permission of The Codehaus. "groovy" is a registered
027        trademark of The Codehaus.
028    
029     5. Due credit should be given to The Codehaus -
030        http://groovy.codehaus.org/
031    
032     THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
033     ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
034     NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
035     FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
036     THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
037     INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
038     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
039     SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
040     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
041     STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
042     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
043     OF THE POSSIBILITY OF SUCH DAMAGE.
044    
045     */
046    package org.codehaus.groovy.ast.expr;
047    
048    import java.util.ArrayList;
049    import java.util.Iterator;
050    import java.util.List;
051    
052    import org.codehaus.groovy.ast.ClassHelper;
053    import org.codehaus.groovy.ast.GroovyCodeVisitor;
054    
055    /**
056     * Represents a String expression which contains embedded values inside
057     * it such as "hello there ${user} how are you" which is expanded lazily
058     * 
059     * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
060     * @version $Revision: 3419 $
061     */
062    public class GStringExpression extends Expression {
063    
064        private String verbatimText;
065        private List strings = new ArrayList();
066        private List values = new ArrayList();
067        
068        public GStringExpression(String verbatimText) {
069            this.verbatimText = verbatimText;
070            super.setType(ClassHelper.GSTRING_TYPE);
071        }
072    
073        public GStringExpression(String verbatimText, List strings, List values) {
074            this.verbatimText = verbatimText;
075            this.strings = strings;
076            this.values = values;
077            super.setType(ClassHelper.GSTRING_TYPE);
078        }
079    
080        public void visit(GroovyCodeVisitor visitor) {
081            visitor.visitGStringExpression(this);
082        }
083    
084        public Expression transformExpression(ExpressionTransformer transformer) {
085            Expression ret = new GStringExpression(
086                    verbatimText,
087                    transformExpressions(strings, transformer),
088                    transformExpressions(values, transformer));
089            ret.setSourcePosition(this);
090            return ret;        
091        }
092    
093        public String toString() {
094            return super.toString() + "[strings: " + strings + " values: " + values + "]";
095        }
096    
097        public String getText() {
098            return verbatimText;
099        }
100    
101        public List getStrings() {
102            return strings;
103        }
104    
105        public List getValues() {
106            return values;
107        }
108    
109        public void addString(ConstantExpression text) {
110            if (text == null) {
111                throw new NullPointerException("Cannot add a null text expression");
112            }
113            strings.add(text);
114        }
115    
116        public void addValue(Expression value) {
117            // If the first thing is an value, then we need a dummy empty string in front of it so that when we
118            // toString it they come out in the correct order.
119            if (strings.size() == 0)
120                strings.add(ConstantExpression.EMPTY_STRING);
121            values.add(value);
122        }
123    
124        public Expression getValue(int idx) {
125            return (Expression) values.get(idx);
126        }
127    
128        public boolean isConstantString() {
129            return values.isEmpty();
130        }
131    
132        public Expression asConstantString() {
133            StringBuffer buffer = new StringBuffer();
134            for (Iterator iter = strings.iterator(); iter.hasNext();) {
135                ConstantExpression expression = (ConstantExpression) iter.next();
136                Object value = expression.getValue();
137                if (value != null) {
138                    buffer.append(value);
139                }
140            }
141            return new ConstantExpression(buffer.toString());
142        }
143    }